Lightener is a term that is commonly used to describe a substance or product that is capable of brightening or lightening hair. However, there are several synonyms that can be used interchangeably with this word to add variety to your vocabulary. Some examples include 'bleach,' 'blonding agent,' 'whitener,' 'clarifier,' and 'decolorizer.' Each of these words refers to a substance that helps to strip hair of its natural color and give it a lighter, brighter appearance. By using synonyms for lightener, you can add depth and nuance to your writing and speech, making your language more interesting and engaging.